Normalize messy lists and table columns with Clean List

Clean List recognises the most common “list-shaped” text you end up with after copy-pasting from a spreadsheet, a terminal, a Markdown table, or a SQL query result, and collapses it into a single compact, comma-separated line:

• One item per line — a newline-delimited list (from a spreadsheet column or a grep output).
• Padded comma list — values already comma-separated but with inconsistent spacing or trailing commas.
• Single-column SQL table output — the kind you get from SELECT id FROM users run in a psql / MySQL CLI, complete with pipe borders and header separator lines.
• Single-column Markdown table — a | value | column.
• Bracketed array — a JSON array or a Python list literal, stripped to just the values.

The result is a compact comma list — no brackets, no spaces, no trailing commas — that you can paste directly into a SQL IN (…) clause, a config value, or anywhere else.

Clean List is deliberately conservative: it rejects multi-column tables (a two-column id,name CSV or pipe table) and refuses prose or multi-word cells rather than silently mangling them, so a stray click can't quietly destroy non-list text — you get a clear error toast instead.

1. Paste the messy list into the Yellorn editor. The format does not matter — Raw Text works fine, or Yellorn will auto-detect if it looks like JSON or CSV.
2. Open the Format menu in the editor toolbar (the split button whose primary action is Smart Format) and choose Clean List under the Minify group.
3. The editor content is replaced with the normalised comma list. One ⌘ + Z reverts if you need the original back.

Build a SQL IN clause from a spreadsheet column

Copy a column of ids from Excel or Google Sheets (you get one id per line), paste into Yellorn, click Clean List, and paste the result into your query:

-- Before (copied from spreadsheet):
1001
1002
1003
1004

-- After Clean List:
1001,1002,1003,1004

-- Ready to paste:
DELETE FROM orders WHERE id IN (1001,1002,1003,1004);

Tidy up psql or MySQL CLI output

Running a quick SELECT in the terminal gives you a formatted table. Clean List strips the borders and header:

-- Before (psql output):
 user_id
---------
 42
 87
 101
(3 rows)

-- After Clean List:
42,87,101

Flatten a JSON array into a comma list

// Before:
["alpha", "beta", "gamma", "delta"]

// After Clean List:
alpha,beta,gamma,delta

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